import Vue from 'vue';  
import Vuex from 'vuex';  
  
Vue.use(Vuex);  
  
export default new Vuex.Store({  
  state: {  
    cart: [  
      { id: 1, name: '手机', price: 1000, quantity: 1 },  
      { id: 2, name: '电脑', price: 2000, quantity: 1 },  
      { id: 3, name: '键盘', price: 200, quantity: 1 },  
    ],  
  },  
  getters: {  
    cartTotal: state => {  
      return state.cart.reduce((total, item) => {  
        return total + item.price * item.quantity;  
      }, 0);  
    },  
  },  
  mutations: {  
    updateQuantity(state, { id, quantity }) {  
      const product = state.cart.find(item => item.id === id);  
      if (product) {  
        product.quantity = quantity;  
      }  
    },  
  },  
});